You're probably like billions of other people on the planet earth, happily going about your
daily life without a care in the world for any of the fundamental forces that make life
on earth possible.
Yet even as you watch this video, one of those forces is experiencing an unexplained anomaly
and unexpectedly weakening, potentially leaving the earth vulnerable to the almost complete
extinction of life.
If what scientists are watching develop in real time persists, humanity has at best years
left to live, and the only thing to survive us will be microbial life in the deepest caves
or darkest depths.
In 1958 it was well understood that the sun sent a steady stream of very dangerous high
energy particles and radiation crashing towards the earth.
What kept life safe from this peril was the earth's powerful magnetic field, stretching
out thousands of miles into space and shielding us from the worst of the solar wind.
So try and imagine their horror when scientists in 1958 discovered that this invisible shield
we rely on for life to continue on earth, was actually weakening.
Known as the South Atlantic Anomaly, it is an area of weakening magnetic field that grows
on average by 12.4 miles per year (20 km).
The area has been closely monitored since its discovery, and today this chink in the
earth's protective armor comes down to just over 100 miles over the surface of our planet.
The anomaly has already taken a devastating toll on manned and unmanned spacecraft, and
modern satellites can't operate in the area without special precautions- or risk destruction.
But what is this anomaly exactly, and why is it so dangerous?
Texans might not like it, but the truth is all life on earth is solar powered- yes, even
you.
The food you eat either ate food that got its energy from the sun, or was food that
got its energy from the sun.
For the kids in the cheap seats, we're talking about plants here.
The sun is basically the giver of all life, but it can also be the taker of that same
life.
That's because all that nice warm sunshine you enjoy on a sunny summer day is only a
tiny percentage of the energy the sun is blasting out into space in your direction.
Basically, the sun is blasting a pure murder-hate beam of radiation straight at your dumb face,
but good guy earth is there to shield you from the worst of it so all you feel is a
nice warm ray of light and maybe some slight sunburn.
That's thanks to the earth's magnetic field, which is generated by the movement of molten
iron and nickel in the earth's core.
All that moving and shaking of those metals in our molten core generates a massive electrical
current, which in turn creates a magnetic field which stretches out deep into space.
That magnetic field is in effect a shield, which deflects or traps harmful solar wind
and ensures that instead of your DNA being blasted apart, you'll at worst suffer a sunburn
from staying outside too long.
But just how bad could it really be if the magnetic field were to collapse suddenly?
That's a great question, and we're glad you asked.
Four and a half billion years ago Mars had a thick, luscious atmosphere, and plenty of
liquid water to go around.
We can see evidence of huge lakes and rivers all over the surface of the planet, and we
know from studying the chemistry of the planet that it was once wrapped up in a thick atmosphere.
Then, everything changed- in geological time scales, practically overnight.
The world that may have once held an advanced dolphin species capable of space flight- you
can't prove that didn't exist- is today only a dusty rock.
The killer?
Its magnetic field.
Scientists still don't understand why Mars' magnetic field shut down, but they believe
that it was due to its smaller size compared to earth, as well as the composition of its
core.
The earth is bigger than Mars- almost twice as big- which means we have a large molten
core that would take longer to cool than Mars' own core.
But that might only be part of the picture.
Rock is a great insulator, that's why our core has remained molten so long- but it's
not just heat from its original formation that's still keeping the core hot, but also
the decay of radioactive elements inside our core that's helping to keep things nice and
warm.
Some scientists suspect that Mars lacked such heavy radioactive elements in its core, which
would have led to a much faster cooling core than the Earth's own.
With a weakening magnetic field, the solar wind sandblasted Mars' atmosphere away, and
eventually, its water.
Any life- such as space-faring dolphins- would have been bombarded by cosmic and solar radiation,
their DNA destroyed by high energy particles ripping it to pieces.
Unless that life moved deep underground, extinction was quick to follow.
And now, it may happen here on Earth.
The South Atlantic Anomaly has been closely monitored for decades, and has now split into
two 'valleys' that continue to move across the ocean and grow in size.
However, it's not quite all doom and gloom just yet, as new data shows that the anomaly
may perhaps be part of a natural cycle that's been going on for millions of years.
We already know to expect anomalies in the Earth's magnetic field, and that's because
the molten core is not uniform in its iron and nickel content- who's motion generates
the magnetic field.
These irregularities in content will inevitably lead to irregularities in the strength of
the magnetic field around the earth, and thus the Southern Atlantic Anomaly is born.
There's no evidence that the earth's magnetic field ever weakened to the point of causing
a mass extinction event, so scientists are hopeful that the SAA will continue to evolve
over time before eventually correcting itself.
For now the greatest danger that the SAA poses is to low earth satellites, which frequently
pass through the anomaly.
They must be careful to shut down sensitive electronics or suffer serious consequences-
such as a Japanese satellite that destroyed itself when charged particles slipping through
the weakened magnetic field damaged some of its electronics.
Even the space shuttle experienced the shutting down of laptops as it flew through the anomaly,
and the ISS regularly passes through it but thanks to its thick shielding suffers few
if any ill effects.
While scientists don't expect the SAA to lead to a magnetic field collapse, there may be
no telling how the Southern Atlantic Anomaly evolves in the future.
If things take a turn for the worse and the anomaly dips below the atmosphere- something
it is already dangerously close to doing- it could spell disaster for any living beings
in the geographic vicinity of the anomaly.
Thankfully for now the anomaly is over the Southern Atlantic, but as it moves and grows
it could eventually pass over heavy population centers.
What the Southern Atlantic Anomaly means for life on earth is still largely unknown.
Before we’re all disintegrated by an angry sun, go watch Worst Natural Disasters In Human
History, or click this other video instead!